


Fortune Favours the Vindictive

by Reavv



Category: Katekyou Hitman Reborn!
Genre: Alternate Universe - Arranged Marriage, Alternate Universe - Future, Crack, M/M, Painplay, Plot What Plot/Porn Without Plot, Post-Canon, Rimming, Rough Sex
Language: English
Status: Completed
Published: 2016-07-04
Updated: 2016-07-04
Packaged: 2018-07-21 13:59:45
Rating: Explicit
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 4,517
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/7389994
Author URL: https://archiveofourown.org/users/Reavv/pseuds/Reavv
Summary: <blockquote class="userstuff">
              <p>Tsuna and Xanxus get married. Tsuna and Xanxus get even.</p>
            </blockquote>





	Fortune Favours the Vindictive

**Author's Note:**

> I started writing this before I saw this post http://kyogre-blue.tumblr.com/post/146641975500/prompt-anyany-arranged-or-political-marriage but you can consider it part of the same universe if you want. This came about because my BETA is a filthy porn enabler, and by the time I had the sex written I didn't want to write the plot.

They go crashing into the wall like the forces of nature that they are, and the only thing that keeps the wood from cracking is that the full regard of their wrath is on each other.

“Those fucking manipulative assholes,” Tsuna growls into Xanxus’s mouth. The taller man (not that much taller, he notes, not after Tsuna’s newest growth spurt) growls back, a feverish look in his eyes.

“I’ll kill them,” Xanxus grits through the lust trying to bring both of them under. As is traditional for a Vongola wedding, the meal they had shared an hour ago was wroth with food meant to bolster libido. Because Vongola can never do anything half-assed, they even work.

“I call dibs on Reborn,” Tsuna gasps, letting the larger man push him farther into the plaster. It’s hard to tell if they’re fighting or fucking, because the bites Xanxus leaves on his neck are savage enough to be mistaken for an attack. He reaches up and pulls on the thick strands of Xanxus’ hair and laughs breathlessly at the muffled growl that rises up in response.

“You know,” he says slowly, with a grin creeping up his face, “they probably expect me to lock myself up in a separate room in embarrassment, or for you to try to kill me in rage. Then they can preach to us about the duty of marriage blah blah blah, never mind that we weren’t the ones who wanted it in the first place.”

Xanxus huffs, but slows the gnawing on his neck.

“So?”

Tsuna grabs onto the lapels of Xanxus’s suit and heaves them around, so that he’s the one crowding the other man into the wall. He pushes one leg so it’s riding the seam of his crotch and grins at him with bared teeth. He knows Xanxus could push him off if he wanted, that he lets Tsuna have a semblance of control out of his own sense of honour. He’d argued first that Tsuna was too weak, too young. But Tsuna has already demonstrated his ability to beat Xanxus, and although he might be younger, he is certainly no longer young.

Xanxus has no scruples killing Tsuna, but marrying him is another story.

“So,” Tsuna drawls, his anger at the situation and his determination to make it better colouring his voice, “the last thing they expect from us is to actually go through with it.”

Xanxus’s raises a brow but doesn’t disagree. The heat between them is cooling down, burned away by their flames. It’s easier to breathe in the room now, skin still feverish but in a good way, in a way that feels like the end of a fight.

“What, you wanna give them a show?” he asks, derisively. His arms pull him closer though, and Tsuna laughs into his mouth as they go back to their biting kisses. They switch sides again, and this time Xanxus keeps him crushed to the wall with enough force that Tsuna knows he’s not getting out. He grabs at Tsuna’s wrists and pulls him up, so that his arms are over his head and held in one hand.

“How about it, feel like fucking me against the wall?” Tsuna pants, hitching further up as Xanxus’ other hand digs into the top of his thighs.

Xanxus growls and shifts Tsuna higher up so that his toes are barely touching the floor.

“Where’d you get such a filthy mouth, huh?” he mutters, and then interrupts Tsuna’s answer by letting go of his wrists to grab hold of his shirt and pull. The flame resistant fabric tears like paper under his hands.

Tsuna laughs breathlessly and surges forward, slipping his freed hands under Xanxus’s expensive silk shirt. The hard muscle and soft skin—interspersed with knotted scars—jerks a little under his touch. Tsuna tries to think if he’s ever seen Xanxus touch someone when not fighting, and comes up blank. He’s never seen him look twice at the dolled-up ladies who entertain the other men, or the young boys too eager and too desperate to climb the ranks.

Tsuna’s not sure he’s seen him look at anyone twice, really.

“Why does—” he huffs as he starts unbuttoning Xanxus’s shirt, “—everyone think I’m still fourteen?”

Xanxus doesn’t answer, just sucks another hickey into Tsuna’s neck and presses bruises into his skin. Since the older man seems content to stick to his ministrations, Tsuna takes it upon himself to get rid of the rest of their clothing. The shirt and jacket is shucked easily, but the pants are a different story. It’s somewhat hard to do with Xanxus in the way, and he ends up resorting to literally burning them off. His clothing goes up in flames too, despite supposedly being flame resistant.

“Fuck!” Xanxus growls, but pulls back from Tsuna’s reddened skin with something that feels more like rekindled lust than anger. He grapples with suddenly naked skin and pulls them away from the wall to stumble towards the bed. Little flickers of left over flame splatter to the floor, burning cheerfully in the darkness of the room.

“Thought you were going to fuck me against the wall?” Tsuna gasps as he’s thrown onto the opulent bedspread, before squeaking as Xanxus heaves himself over onto him.

“Tempting, but it’s even more tempting to ruin Nono’s fucking expensive bed and then break all the furniture fucking you across it,” Xanxus says, teeth bared and hands settling on Tsuna’s hips.

“Oh, carry on then,” he says faintly, watching Xanxus work.

“I don’t got lube,” Xanxus says, pushing Tsuna further up the bed, “fuckers probably didn’t think that far ahead, as usual.”

“Wouldn’t be the first time,” Tsuna mutters, shifting his legs restlessly across the soft blankets. He gets a startled glance, and then quiet laughter.

“You’re a surprisingly kinky fucker, aren’t you? Don’t matter, this won’t be like those other times.”

Tsuna doesn’t have time to ask what he’s talking about, because that’s when Xanxus lifts Tsuna’s hips up and opens his mouth around Tsuna’s dick.

Tsuna, embarrassingly enough, squeaks. So does the bed, when he kicks out and accidently hits the wall. He can feel Xanxus’ grin against his skin.

“Xanxus!” He tries squirming out of his grip, but that just makes the other man hold him down tighter and nip at the crease of his thighs. He sucks an angry looking hickey right over the largest vein of his leg and digs his nails in.

Tsuna snaps out and grabs onto the bedpost, deposing lush pillows as he does, and tries not to melt the bed in his suddenly steaming grip.

“Stay still, trash,” Xanxus murmurs and then moves his mouth back up, nosing through curls and running a rough tongue along sensitive skin.

The blow job is distracting enough, not just in the act but the fact that Xanxus is doing it, that he doesn’t realise at first that his hands have left Tsuna’s hips.

“What are you doing?” he asks groggily, trying to push himself up to get a better look. Xanxus’s hands are reaching back, disappearing behind his impressive back.

Xanxus pulls off with a pop, stretching up and grinning down at him.

“What?” he rasps out, smug and practically glowing with it. Tsuna shudders.

“Fuck,” he blows out another breath and then laughs shakily, “in that case we really need to find lube, I don’t think I’m experienced enough not to make it hurt.”

Xanxus sneers.

“I’m not as weak as you are, trash. You want roses and chocolate you can go crying back to your girlfriend.”

Tsuna jerks up.

“Kyoko isn’t my girlfriend!”

A hand goes snapping out, clenching around his neck and forcing him back down. Xanxus settles back against his hips and the friction more than anything keeps Tsuna where he is.

“I was talking about your fucking storm guardian,” Xanxus sneers into his face, hand still on his neck. Just the thought about what Gokudera is going to say when Tsuna comes back with finger shaped bruises and hickeys has him giggling.

“Fine, then let me, here—” Tsuna rasps, wiggling out of Xanxus’s grip. The man lets him go only after pressing down hard on his windpipe in warning first.

Tsuna lets his hands creep up Xanxus’s torso as he shifts down on the bed, so that the man is straddling his chest instead of his hips. His eyes stray to the dick that’s now leaving sticky trails on his pecs. It’s a nice one, as far as dicks go, proportional and nicely shaped. He’s amused to note that Xanxus trims down there, but that’s as far as his judging goes before he pushes up to pay the man back.

He starts by nipping at his hips, laying small feathery kisses on every scar he comes across, paying special attention to the ones he knows are from flame damage. He strays further up, dragging his teeth across the taut abs.

Xanxus hums consideringly and grabs at Tsuna’s thick hair, pushing his head further down. Tsuna grins into his pelvis but obliges, laying a gentle kiss on the tip of his dick.

He’s not being a tease on purpose, mostly. He’s just not used to being able to take his time with things like this, since it’s not like he has a lot of personal space or time to go out and fuck someone. Most of his experience is with darkened clubrooms and back alleys.

Xanxus doesn’t let him get away with much more gentleness, because it doesn’t take more than a few kittenish licks for him to grunt and then push Tsuna down again, this time not letting go until he gets the point and opens his mouth for real.

“Jesus fuck, your mouth,” slips out of Xanxus’ mouth, but Tsuna isn’t sure if he’s supposed to have heard that so he ignores it. The pointed thumb digging into the corner of his lips is less ignorable. The slow thrusts of his hips even more so.

Tsuna closes his eyes and focuses on breathing, hands digging into the tops of Xanxus’ legs as his own erection goes untouched. It’s calmed down a little from lack of attention, but the syrupy glow burning behind his stomach from Xanxus’s cock in his mouth makes up for it.

The sound of clattering wood has his ears perking, but with one hand still on the back of his head he can’t do more than suck inquisitively at the sound. Xanxus curses.

“If I didn’t have to listen to the old man talk all the time about your supposed destiny, I would think you were meant for this, trash,” he mutters, before the snick of a cap popping rings out, Xanxus’s hand retreating at the same time.

Tsuna pulls off slowly and risks a glance up, watching as Xanxus coats a couple fingers with what appears to be all natural hand cream.

“Wait, wait a second,” Tsuna gasps out, pushing himself even further down and grabbing at Xanxu’s hands at the same time, “let me just, I want to—”

He doesn’t finish, and instead presses a kiss to the crease between Xanxus’s leg and ass. He can feel Xanxus jerk a little, but he pushes on forward without looking back. He has to let go of his hands to pull him down, but it’s worth it for the shaky curse that Xanxus grates out.

“Jesus! What the hell do you—You’re one kinky son of a bitch, Sawada,” he grits out, breath heavy, “where did you even fucking learn something like that, trash?”

Tsuna grins against the soft skin and noses gently at his perineum, before getting back to business. He starts small, open mouth kisses at the rim intersperses with quick kitten licks. When he feels the muscles under his hands bunch up he pulls back and bites at the skin stretched across the generous glutes.

“Fuck,” Xanxus curses again, slumping a little, letting his legs widen a little more. Tsuna hums smugly and inches closer.

This is something Tsuna actually loves doing, male or female. There’s something about the messiness of it, the filthiness of it, that really gets him going. He likes being able to go down on someone and have them gasp out his name in surprise and pleasure.

He likes proving that, despite what his guardians seem to think and Reborn continues to say, he’s not a kid any longer.

He points his tongue and starts varying his motions a little, taking the time to try and dip in on every down stroke, trying to loosen up muscle and not just shock the man on top of him. The legs clamped around his head twitch every time he does.

“God fucking damn,” Xanxus burst out, as his tongue inches in slightly. His whole body shivers as Tsuna’s tongue sinks a little farther in. That seems to be the end of Xanxus’s patience though, and he pulls Tsuna off and up roughly with one hand, teeth sinking back into his neck as soon as he’s in reach. The feathers in his hair tickle Tsuna’s face.

“Xanxus, can I—let me—” Tsuna stutters when he pulls back, hands going towards the bottle again. Xanxus sneers and pushes him down on the bed.

“As if I would trust your fucking flame hands anywhere near my ass,” he grits out, dropping the bottle on Tsuna’s chest. “Slick yourself up if you want to be good to me.”

Tsuna groans, but reaches out to take the lotion anyways. He wants to be on top for this part, to see what Xanxus is doing and how he’s touching himself, but being able to look up into his face and see his expression twist is almost good enough.

Xanxus doesn’t seem capable of taking his time, sooner than Tsuna thinks sensible he’s grabbing at his—now slick—dick and leaning forward to catch the stretch of Tsuna’s neck in a sharp bite.

“F—fuck,” Tsuna squeaks, partly at the pain and partly at the feeling of his dick pushing into Xanxus ass. It’s still tight, but Xanxus doesn’t let either of them adjust before he’s pushing back and starting up a punishing pace.

It hurts, slightly too much friction and—despite the way Xanxus is bouncing on Tsuna’s cock—it feels more like he is the one being fucked. The bite to the neck is only the beginning, Xanxus reaches back and scores lines of nail marks down Tsuna’s thighs when he whines, takes a nipple between sharp teeth and draws blood, makes finger shaped bruises on his arms and wrists and hips.

Maybe from the years of being Reborn’s kick toy, of fighting and hurting and always being the weakest in the room, the pain registers less as pain and more as a challenge. It feels like Xanxus is saying: “I don’t see you as weak, see? See how strong you are.”

Maybe they can make this marriage work. Maybe Xanxus won’t kill him and maybe he won’t kill his father for forcing him into this position (or maybe he will), and maybe they will even do something besides fuck and fight. But at least he knows now that Xanxus likes him enough to fuck him in the first place. That’s a start.

The bed groans with the frantic motions of both their hips, and Tsuna can feels himself slide further up the blankets with the force of it. He opens his eyes to see Xanxus’s lips twist into something halfway between a snarl and a sharp grin.

“Gonna moan for me, trash? Gonna let everyone outside hear who’s fucking you tonight? Make sure no one in this shitty castle can sleep tonight?” he growls. Tsuna feels his eyes close and a moan slip out unbidden.

“Yeah,” Xanxus whispers, “C’mon, Sawada.”

Tsuna’s heart is racing, blood rushing to his head and his dick and he feels like a teenager again, a gasp away from orgasm. Xanxus runs hot, flames licking just under his skin and he feels like he’s going to burn up from the intensity of it.

“Harder,” Tsuna gasps into Xanxus’s mouth, and the look on the other man’s face is worth the pain in his hips. He feels his wrist bones grind under Xanxus’s hands, feels his toes curl down and his leg kick out. He even feels his lungs burn in his chest.

He doesn’t hear himself scream.

—

Later, after his body is still twitching through the aftershocks and Xanxus is lazily stretching out besides him, he feels the rasp of his voice and chuckles.

“What do you want to bet that at least one person out there thinks you were killing me in here?”

Xanxus grunts.

“With the things you were screaming? Be a pretty fucked up murder,” he mutters into the pillows. Tsuna hums.

“I don’t think I can feel my legs,” he says, after a few minutes of slowly curling his fingers into the duvet.

“I don’t think I can feel my fucking dick,” Xanxus grumbles in response.

Both of them lie there for a few more minutes, silently. Tsuna blinks up at the elaborate crown moulding of the ceiling and snorts.

“Fuck, ok. One of us has to go down there to see the look on their faces.” He rubs at his eyes and levels himself up, shivering now that he’s not pressed up against the heat of Xanxus’s skin.

“Trash,” Xanxus mutters, almost inaudible. Tsuna’s not sure whether he’s calling him trash, or the people downstairs. He doesn’t really care either.

He shuffles down the bed, noticing as he does that the sheets are singed and the headboard broken, and swings his legs off the bed. They’re shaking. So are his hands, and now that the adrenaline is leaving his system he’s feeling every single one of his aches.

He snags Xanxus’s shirt—the only intact piece of clothing—and shrugs it on. It’s big on him of course, wider in the shoulders and reaching his upper thigh, but that just makes his current look even better. He undoes a few of the top buttons and studies himself in the vanity mirror, before fluffing his hair up even more and pinching his cheeks.

There’s the sound of a grunt behind him and he glances back to see Xanxus ambling towards him, long limbs on display and bright eyes staring at him. Tsuna lets himself look, appreciatively.

“You ruin my shirt and I kill you,” Xanxus says, slipping a hand under said shirt and onto his hip. He bends down and sucks another hickey into the back of Tsuna’s neck.

He pulls back and grins at Tsuna through the mirror.

“Fucking destroy them,” he growls, and then lifts him over a shoulder and throws him bodily out of the room.

—

There’s a heavy silence at the Vongolan breakfast table that Reborn lets simmer. A few manically sleep-deprived idiots are clustered together looking like it’s the end of the world, but for the most part everyone else just looks awkward. It’s four am, and no one besides Lambo has slept a wink after the wedding after party. Halfway through the celebrations—categorised by alcohol and explosions—someone noticed the noise coming from the upstairs married suite and made a comment, and it just devolved from there.

Reborn himself feels a sort of pride for his student, finally learning what it means to be a married man.

Iemitsu on the other hand needed to be physically restrained from interrupting, and repeatedly reminded that it was partly his idea in the first place to unite the crumbling factions of Vongola by a wedding vow.

His face seems to be stuck in perpetual shock, complimenting Gokudera’s own wide-eyed look nicely.

Reborn takes a sip of espresso and hides a smirk in his cup.

The others at the table—Tsuna’s guardians and the Varia mostly—are all in various states of shock, but it’s those two that seem the worst off. Takeshi is even smiling, as if hearing his best friend get brutally fucked by a man who once wanted to kill him is an average Friday night for him. Who knows, maybe it is.

“Hmm, well it appears that they are done for now,” he muses, when no more moans or screams are heard through the shitty soundproofing. Iemitsu moans and thunks his head on the table, pulling a blubbering Gokudera down with him. Takeshi laughs, and then ends up having to duck Squalo’s swipe to the neck. The Varia on a whole look mostly unconcerned, except maybe for Levi who hasn’t stopped crying in a corner the whole night. The only ones even here this morning are Squalo, Levi, and Lussuria.

“Enough!” Iemitsu snaps, jerking his head up off the table, “I can’t handle it anymore—”

“—Handle what?” A voice rasps from behind them. There’s a pause as those unobservant enough jump. Reborn takes another sip of espresso and eyes his student sharply.

From the sex-mussed hair to the flushed skin of his face, all the way down the bite makes on his bared thighs, Tsunayoshi looks completely ravished. He’s wearing Xanxus’s shirt, and nothing else but the bruises littering his body.

“A mafia boss should never show up in such an indecent state,” Reborn chides, ignoring the chaos that his student’s arrival has sparked in the idiots around him. Iemitsu in particular looks like he’s dying.

Reborn surveys the guardians and counts them off silently. Chrome blushes to the roots of her hair but smiles a greeting to her boss anyways. Ryohei doesn’t seem to react at all. Lambo was rushed over to the guesthouse with Kyoko and Hana as soon as the drinking started and Hibari left after being assured of a fight the next day.

“Haha, you got something right—there,” Takeshi laughs, pointing to the finger shaped bruises on his neck. There’s a sharp look in his eye though, and a tenseness in his shoulder that belays his easy greeting. Reborn makes a mental note of his protective instincts and approves.

“EXTREME!” Ryohei sticks up a thumbs up and winks.

“TE-ENTH! Do you—Do I, I’ll kill—ugh,” Gokudera splutters, redness rising in his face and eyes glued to Tsuna’s body. Reborn notes idly that the boy halts halfway from standing and hunches in a little over the table.

Tsuna blinks wet eyes and smiles at him.

“You can’t kill my husband, Hayato. That’s something only I get to do.”

Both Iemitsu and Gokudera choke. Reborn nods approvingly.

His student drags back a chair besides Lussuria and tugs the coffee jug closer. He gets a blinding smile from the man and a wink.

“Hmm, honey, you look positively ravished,” Lussuria purrs, making Gokudera moan in agony and also reach for his dynamite. Tsuna nods, as is due, and accepts the high-five he gets in return. On his other side Chrome nonchalantly elbows Gokudera in the ribs, making him drop his bomb.

Reborn watches this all placidly.

“Looks like the shitty boss tried to eat ‘cha,” Squalo retorts, a grimace on his face as he leans away from the table, “Fuck, I’m out of here. I only stayed long enough to see if you died or not.”

“That’s not very courteous to say to your boss’s new husband,” Reborn says mildly, hooking one leg on Squalo’s chair and forcing him back into the table.

“Fuck you!” Squalo yelps, snarling. Takeshi grins and rests his hand next to his propped up sword, only for the man to swing his head around and snarl right into his face too.

Tsuna ignores the byplay with longstanding practice and accepts the plate of food Chrome hands him instead.

“As long as you’re happy,” she says, blush only fading a little. A strange look crosses her eyes for a second.

“Although Mukuro-sama might not be as happy,” she muses, and then ignores his questioning look. Reborn makes a mental note of that and files it away for later.

“No way! Tenth, you—you can’t be h-happy with Xanxus! You didn’t even want to get married! He’s a crazy murderer—”

“—Hey!” The Varia members present snap.

“—who’s already staged a c-coup and, and, anyways, he’s obviously too much of a violent asshole—”

Gokudera chokes and Tsuna blinks at him worriedly as his lips turn blue. He feels a heavy hand land on his shoulder and looks up into Xanxus’s scowling face. Reborn watches Squalo flinch and Lussuria grin, Takeshi’s eyes narrow and Chrome’s blush return, and then snags the back of Iemitsu’s shirt so he doesn’t get killed trying to defend his son’s virtue.

“What you saying, trash?” Xanxus rumbles threateningly. He’s not wearing a shirt, and whatever pants he found in the suit are obviously not his because they stretch obscenely across his front. Tsuna drags his eyes down the bared skin and grins at the marks he can see starting to purple. His eyes linger particularly on a set of handprints on either side of his hips. Reborn is relieved to see that his student didn’t just roll over and take it.

“You monster!” Iemitsu cries, large crocodile tears slipping from his eyes, “deflowering my poor Tsu-kun—”

Tsuna laughs, loudly, and interrupts his father.

“Dad, dad. Xanxus didn’t deflower me. For fucks sakes, I’m twenty four, I’ve been having sex for years now.”

A silence falls down on the group. Reborn feels his coffee mug crack under his hands. The only one not to tense up or gape is Ryohei, more concerned with his food than anything else.

“What.” Iemitsu grits out. Tsuna blatantly ignores him and looks back at Xanxus.

“Where’d you find the pants? I thought I burnt the rest of our clothing?” he asks slowly, tugging at the collar of the shirt he’s wearing. Reborn’s eyebrow rises on it’s own, wondering amusedly if the very elaborate marriage room survived. Between Tsuna’s Sky flames and Xanxus’s Wrath flames, it’s very possible it didn’t. 

Xanxus snorts and doesn’t answer, instead grabbing Tsuna by the arms and lifting him up.

At once the tense people at the table stand, reaching for weapons. Flames rise up to the surface, and Reborn grabs Leon in his gun form, not bothering to use blanks.

Xanxus grins and sits on the now unoccupied chair, plopping Tsuna in his lap as he does. The aggression in the air bleeds into confusion. Reborn puts Leon back on to his hat and sits down. He heats up his now cold espresso with a snap of sun flames and brings it up to his lips in thought.

He’s pretty sure he was the only one to notice Xanxus’s wince as he sat down, which is an interesting tell for the man to have. Maybe he’s taught his student more than he thought. He’s obviously inherited Reborn’s own sadistic love of confusing and frustrating the people around him.

“W-what?” Gokudera splutters, over Takeshi’s laugh and Iemitsu’s growl. Lussuria whistles appreciatively, going for another high five, blocking Squalo’s flailing arms as he does.

Reborn watches the way Tsuna and Xanxus share a smirk and sighs. Ah, young love.


End file.
